Regulations for laser lit holograms?

[Ed Wesly]

I guess I am a lurker here, since I don’t post very often, probably because I use lasers for holography, but always enjoy the banter here. I was hoping people here could assist me with a project.

I am helping set up an exhibit of a couple of laser lit holograms at a major cultural institution in Chicago. Since they are going to be laser lit with a divergent spread beam, it doesn’t appear that this kind of display falls under the laser safety rules of scanning laser light shows. Or does it?

The installation of the exhibit will simply have a 10 mW He-Ne directed at each of the holograms at the appropriate reconstruction angle, with a spatial filter attached to the laser directly, so there would be no access to the undiverged beam. The spread beam would illuminate the hologram, no scanning involved. Would the image light coming to the viewers’ eyes need to be under a certain MPE? I tried searching the FDA site, but couldn’t find anything about this situation.

Does anyone here have any experience with complying with the rules for this type of laser display? Any help, anecdotes, or pointing me in the right direction would be greatly appreciated.

[gottaluvlasers]

Hi Ed-

"Technically" This still does fall under the realms of a Laser light show. Any time a Laser is operated in public for display purposes (5mW or greater), it falls under a "Laser light show." Without doing any math, I am 99% sure that your divergent 10mW HeNe beam will be WELL BELOW any sort of MPE at aalmost any distance so I really dont think you need to concern yourself with any safety issues. The only issues you "technically" need to think about are the regultory ones. Again, 5mW or above requires a variance and certified equipment. So, you *do* fall in the regulatory area. However, 10mW, holographic purposes, if you arent operating with a variance i dont think you'll be hung in the public square! I would say go do your display and obviously just keep an eye out (no pun intended) and make sure none of the divergent optics become misaligned to shoot a straight static beam into a crowd.

-Marc

[RonZ]

Hi Ed,

Like you, I mostly lurk here and enjoy the additional perspective on lasers.

My only suggestion might be to contact Seth Rifkin at the MIT museum of holography. He has put on public displays which included He-Ne lit transmission holograms for public display. He may be able to offer some useful information. His contact information is readily accessible on their web page. Ron

[Ed Wesly]

Thank you for all your help! I will post some pictures when the show is up!